1. Field of the Invention
The invention relates to imaging devices, and more particularly to imaging devices for medical and other uses. The invention is particularly useful for imaging vascular structures in patients to aid in the insertion of a needle during venipuncture.
2. Description of the Related Art
Veins and arteries in many patients are difficult to find. This problem is exacerbated in, for example, dehydrated patients, dark-skin patients, and young patients. Further, unskilled technicians have great difficulty in locating subcutaneous structures even in normal patients. Thus, a device to aid in locating such structures is needed.
Attempts at providing such a device include various devices that illuminate skin to enhance location of veins and arteries. These devices use a variety of light sources, such as laser light, infrared light, flashlights, fiber optics, and ultrasonic waves, for illuminating the skin. For example, the device of U.S. Pat. No. 4,817,622 to Pennypacker, et al., which is incorporated herein by reference, illuminates with an infrared light source. Typically, a camera with an image sensor, such as a charged couple device (CCD), or the like is also included to capture an image of the surface below the skin. For example, video and still cameras have been used in such devices. However, none of these devices provided an instrument that produces an image of an acceptably high enough quality to permit rapid and trouble-free finding of vascular structures in patients. In particular, many imaging devices have difficulty handling ambient light, which can interfere with image acquisition and image processing.
In view of the foregoing, it would be desirable to provide a device that permits the detection of a structure or interest, such as, subcutaneous natural or foreign structures in patients and structures above the skin. It would also be desirable to provide a method of using such a device.